Convert your 7900GT into a 256Mb 7900GTX

[t024484]

The biggest functional difference between the GT and GTX is that the GTX switches the Vgpu between 1.2 in 2D to 1.4 Volt in 3D.
Thats why the GTX can be clocked at 650 Mhz in 3D.
EVGA has their 7900GT-SS board with increased hardware in the volt mod area, which also enables the switching from 1.2 in 2D to 1.45 in 3D.

My firm believe is, that this voltage switching extends life of your GPU, since most of the time you are working in 2D, and thus you will have the 1.2 Volts on the GPU.
This can be the only reason that I can think of why the 7900GTX as well as the EVGA7900GT-SS have this feature.

I have made the same voltage switching option to a standard 7900GT. This modification can be applied to any standard 7900GT board. You will need a BIOS that switches from VID 0 in 2D to VID 1 when in 3D mode. You can check if your BIOS does this, with the monitor function of Riva Tuner going from 2D to 3D.
You could use the EVGA 7900GT-SS BIOS for this purpose, but you can just as well change your own BIOS with Nibitor, using the advanced voltage editor.
You will also need some soldering skills.

The components that I used, are 2 dual schottky diodes, type BAT54C, and 1 N type Mosfet BSS670S2L, that's all. I bought them from Farnell.com.
Any dual schottky diode with common cathode will do , and any low power N channel Mosfet with less then 10 Ohm channel resistance when switched on is O.K.

The board in the unmodified state looks like:

48513

And after Modification:

48514

Red gives you +0.05 Volt
Yellow gives +0.1 Volt
Purple gives +0.2 Volt

So with the standard 5Kohm resistor giving you 1.2 Volt in 2D, you can now switch to anything between 1.2 and 1.55 Volt in 3D.

If you change to 50 Kohm, you can go anywhere from 1.5 to 1.85 Volt.

Do not bother what Nibitor is telling you what the exact 3D Voltage is, although it should be different from the 2D voltage, with the advanced editor you can give it the value you like. The thing that is important, is that in 3D the GPU switches to VID 1 from VID 0 in 2D.

With these additions, your board is functionaly 100% comparable with a 256Mb GTX.

[sluggo]

That's great, t024484! Now I can get that wire off my board and run coler in 2D. :) All I need now are a pair of steady hands!

If, instead of using a 5k SMT resisitor I used a dab of conductive paint, would that work or would I end up in a wrong voltage table?

[t024484]

That's great, t024484! Now I can get that wire off my board and run coler in 2D. :) All I need now are a pair of steady hands!

If, instead of using a 5k SMT resisitor I used a dab of conductive paint, would that work or would I end up in a wrong voltage table?
Intersil specificies a 5Kohm resistor, without telling what tolerance should be.
My experience is that 4k7 is still O.K. , but conductive paint with 0 Ohm is wrong without a doubt. I would say, 5Kohm +/- 10%.

[g_aleph_r]

Sorry double post

[g_aleph_r]

Is dangerous to change the vgpu via dip switch with the pc turned on?
I'll never be able to do this mod!!:(

[t024484]

Is dangerous to change the vgpu via dip switch with the pc turned on?
I'll never be able to do this mod!!:(
If you prefer a (dip)switch, I would suggest to switch with the PC turned of.

[alpha0ne]

Thanks t024484 :toast:

A really easy mod if I can get the parts in AU :)

[Roger_D25]

t024484,
Do you still want/need that BIOS you asked about? I'd be happy to send it to your e-mail or I'll give you a linky to it over at mvktech as I uploaded it there the other day (Mavke didn't have it). By the way thank you for all the great work and info you give us all! Until I read a few of your last posts I had no idea what those little black components actually where up next to the D508, D511, and Q516 pads were. There responsible for the switching of 2D and 3D GPU voltages, and there called dual schottky diodes, very interesting! Keep it up man, many of us really apprecaite it!

[t024484]

t024484,
Do you still want/need that BIOS you asked about? I'd be happy to send it to your e-mail or I'll give you a linky to it over at mvktech as I uploaded it there the other day (Mavke didn't have it). By the way thank you for all the great work and info you give us all! Until I read a few of your last posts I had no idea what those little black components actually where up next to the D508, D511, and Q516 pads were. There responsible for the switching of 2D and 3D GPU voltages, and there called dual schottky diodes, very interesting! Keep it up man, many of us really apprecaite it!
Thanks you for your offer, but I aready helped myself by visiting MVKTech.
That's how I found out that you can change any 7900GT Bios by means of the Nibitor Voltage Editor, to have two VID levels.
Silly enough, if you could find how to enable the third and the fourth VID level, you could have your EVGA_SS Bios changed to have 1.55Volt instead of the current 1.45 Volt.
All the hardware, read all the little black fellows, are there to do the switching, all you need is the signal from the GPU to get it switched to 1.55 Volt.

[Roger_D25]

Thanks t024484, glad you found it! Which BIOS version are you specifically using, the stock SS one (14.49) of the slightly modified one that came with my card (14.43)? Just curious, I'm pretty sure they are both the same BIOS but with just a few minor changes?

[Z33ky]

Saw this post at eVGA (http://www.evga.com/community/messageboard/topic.asp?TOPIC_ID=15640) and you'll see in the second post of the string, 2 photos; one before and the other after the return of the 7900GT KO and you'll see that eVGA has done a mod like that shown in this thread.
Card before return:
http://img144.imageshack.us/img144/8447/7900gtunmodified9hk.jpg

Card after return:
http://img144.imageshack.us/img144/1182/7900gtmodified5nx.jpg

By the looks of it eVGA has modified the card so that it to has a seperate VGPU for 2D and for 3D. And in a post further down the string by 'saviorself' he posted the following:

"According to Blue Falcon at [H], the cards are now running 1.2v 2D and 1.45v 3D"

What are your thoughts on the matter t024484? Perhaps buying a new 7900GT KO would be a great idea and one wouldn't have to perform the mod described in this thread? Thanks in advance!

[Roger_D25]

Actually it turns out that eVGA has been given out their SS cards as RMA replacments to some of the people who have gone through multiple RMA's with persistant problems. In fact I just recenlty got mine about 2 weeks ago. At first I thought it was just a modified card but it's actually their SS card. Fortuenlty since this last RMA replacment my card has worked longer than any other RMA replacment so far (fingers crossed). I also think this because on my PCB the BIOS version sticker says xxxxx14.49 which is the only offiical SS BIOS version but when you actualy extract my BIOS it's version 14.43 which is a modified version of the SS one with lower clockspeeds to match the cards they replace. I have measured the cards 2D and 3D voltages and they are indeed 1.2v and 1.45 respectivly using a multi-meter.

The only drawback is that even the people getting this SS card as a RMA replacment are having the same problems they had with their old cards? I hope I'm one of the lucky ones!

[t024484]

Saw this post at EVGA Forum. What are your thoughts on the matter t024484? Perhaps buying a new 7900GT KO would be a great idea and one wouldn't have to perform the mod described in this thread? Thanks in advance!
If you buy a new board, it certainly is worth considering to buy an EVGA board with the 1.2/1.45 switching option already installed, like the KO-SS.
On the other hand, the cost of an GTX is "only" 70,- euro more, so this might be an even better option.

But for those already in the possession of a 7900GT, this DIY option that I have described could be interesting to hopefully extending the life of their board. And let's not forget, this is the Xtreme forum.

Somewhat to my surprise, EVGA have added more components than strictly necessary, because it is not only possible to switch to 1.45Volt (VID 1) but also to 1.3Volt (VID 2) and to 1.55Volt (VID 3).
I cannot find the way in BIOS to have VID 2 and VID 3 enabled, so for the time being the extra hardware is partly of use for nobody.

With my modification, I have used the fact that only the VID 1 line is switched, that's why I achieve exactly the same as EVGA, but with reduced hardware.

As a last remark, my guts feeling tells me that it is the 7900 GPU that is very vulnerable, time will learn.
Because of that EVGA is changing their boards to 1.2 Volt in 2D, why would they invest in extra components if it is not necessary.
But although this switching is a step in the direction, I still read of GTX boards and unmodified 7900GT boards that are dying, so it is not the final solution.

In a previous thread I have already mentioned that with the new 90 Nm chip, things are getting more critical than ever.
1 Volt voltage difference into two conductors only 100 Nm apart, means 10.000Volts per millimeter. Enough to fire a spark plug in a car.
The only difference with a spark plug is that it designed to spark, which cannot be said of a GPU chip. So the design of a 90 Nm chip cannot simply be a downgrade of a previous 130 Nm design.

[t024484]

Thanks t024484, glad you found it! Which BIOS version are you specifically using, the stock SS one (14.49) of the slightly modified one that came with my card (14.43)? Just curious, I'm pretty sure they are both the same BIOS but with just a few minor changes?
At the time I am using a 14.47 version from MVKTech.
There are many changes as compared to my original 12.02 version, but I really have no idea what those changes are doing, and wether they are doing something at all.
It seems that the 12.02 version with the added VID 1 switch setting for 3D, performs just as well as the 14.47.

[Augu]

Nice guide t024484 and it worked just fine. In fact i did it to my frend's card becouse he asked me :D

[Roger_D25]

Thanks again t02448!

[bouc]

really nice, gonna give it a try ;)

[Roger_D25]

bouc are you useing a SS card or just a regular 7900GT?

[bouc]

a regular one (galaxy) why?

edit:
did mod my bios to have two differents vid ;)
looking for components now :D

[Per Hansson]

The pictures in the first post does not load...

[t024484]

The pictures in the first post does not load...
When I try, everything is there.
If you still cannot see them, let me know and I will send them by mail.

[Per Hansson]

When I try, everything is there.
If you still cannot see them, let me know and I will send them by mail.
I tried with 3 different browsers and also asked a friend that sits on a different ISP and the images did not load... Sure yours are not just cached by the browser?

[bouc]

It's the same for me, no more pictures...

[t024484]

It's the same for me, no more pictures...
I cleared my cache, and the pictures where gone.
so here they are again.
Before Mods

49209

And after modding

49210

Red gives you +0.05 Volt
Yellow gives +0.1 Volt
Purple gives +0.2 Volt

So with the standard 5Kohm resistor giving you 1.2 Volt in 2D, you can now switch to anything between 1.2 and 1.55 Volt in 3D.

If you change to 50 Kohm, you can go anywhere from 1.5 to 1.85 Volt.

Do not bother what Nibitor is telling you what the exact 3D Voltage is, although it should be different from the 2D voltage, with the advanced editor you can give it the value you like. The thing that is important, is that in 3D the GPU switches to VID 1 from VID 0 in 2D.

With these additions, your board is functionaly 100% comparable with a 256Mb GTX.

[***Deimos***]

If you buy a new board, it certainly is worth considering to buy an EVGA board with the 1.2/1.45 switching option already installed, like the KO-SS.
On the other hand, the cost of an GTX is "only" 70,- euro more, so this might be an even better option.

But for those already in the possession of a 7900GT, this DIY option that I have described could be interesting to hopefully extending the life of their board. And let's not forget, this is the Xtreme forum.

Somewhat to my surprise, EVGA have added more components than strictly necessary, because it is not only possible to switch to 1.45Volt (VID 1) but also to 1.3Volt (VID 2) and to 1.55Volt (VID 3).
I cannot find the way in BIOS to have VID 2 and VID 3 enabled, so for the time being the extra hardware is partly of use for nobody.

With my modification, I have used the fact that only the VID 1 line is switched, that's why I achieve exactly the same as EVGA, but with reduced hardware.

As a last remark, my guts feeling tells me that it is the 7900 GPU that is very vulnerable, time will learn.
Because of that EVGA is changing their boards to 1.2 Volt in 2D, why would they invest in extra components if it is not necessary.
But although this switching is a step in the direction, I still read of GTX boards and unmodified 7900GT boards that are dying, so it is not the final solution.

In a previous thread I have already mentioned that with the new 90 Nm chip, things are getting more critical than ever.
1 Volt voltage difference into two conductors only 100 Nm apart, means 10.000Volts per millimeter. Enough to fire a spark plug in a car.
The only difference with a spark plug is that it designed to spark, which cannot be said of a GPU chip. So the design of a 90 Nm chip cannot simply be a downgrade of a previous 130 Nm design.

Amen brother.

[bouc]

thanks a lot for pictures t024484 ;)

[bouc]

You are THE ONE t024484 :D

thanks again for everything

mod done (1.4v), with NV silencer 5 rev2 42°C idle 60°C load
2D : 450/1320 1.2v
3D : 615/1680 1.4v :D :D :D

[t024484]

You are THE ONE t024484 :D

thanks again for everything

mod done (1.4v), with NV silencer 5 rev2 42°C idle 60°C load
2D : 450/1320 1.2v
3D : 615/1680 1.4v :D :D :D
Congratulations, I am glad you got it working.

[bouc]

for info, I did modify my bios using nibitor to create second vid, but rivatuner said 2D vid 0, 3D vid 2, then did download an evga SS bios and rivatuner said 2D vid 0 and 3D vid 1.

++

[t024484]

for info, I did modify my bios using nibitor to create second vid, but rivatuner said 2D vid 0, 3D vid 2, then did download a evga SS bios and rivatuner said 2D vid 0 and 3D vid 1.

++
Did you tell Nibitor that you wanted to use VID1 but Rivatuner reported that it was VID2 ?
This is quite strange.

[bl1zZ]

nice guide

[bouc]

Did you tell Nibitor that you wanted to use VID1 but Rivatuner reported that it was VID2 ?
This is quite strange.

yep, that's that, do you want the bios image? maybe a step to more than 2 vid on 7900GT :D

[t024484]

yep, that's that, do you want the bios image? maybe a step to more than 2 vid on 7900GT :D
Yes, I would like to receive it. Just for the reason that we can inform Nibitor that there is a bug in their program.

[bouc]

here it is
http://boucz.free.fr/bios/mod.rom

[4Qman]

t024484,

Awsome work, Ill do this once my 7900GT is returned from RMA.:toast:

[Orion24]

Is it me, or are the mod pictures not visible? I'm highly interested in this mod...

[t024484]

Is it me, or are the mod pictures not visible? I'm highly interested in this mod...
It is still there.
I replublished in posting 24

[Orion24]

It is still there.
I replublished in posting 24OK thanks :) . Just noticed. Now I wonder where do I get to find these staff in my country... :confused: . Anyway, if I get to do this, I'll go for more than 1.55V 3D. The same 2D/3D voltage was keeping me from doing the mod for more volts.

My firm believe is, that this voltage switching extends life of your GPU, since most of the time you are working in 2D, and thus you will have the 1.2 Volts on the GPUI'll disagree. Most people with the problems never overvolted their cards and were at 1.2V all the time. I think EVGA did that to rule out the possibility of of 1.2V beeing insufficient for the overclocked 7900GT cards to run stable.

[t024484]

I'll disagree. Most people with the problems never overvolted their cards and were at 1.2V all the time. I think EVGA did that to rule out the possibility of of 1.2V beeing insufficient for the overclocked 7900GT cards to run stable.
If a lower voltage does not extend life, why has EVGA not simply increased the voltage from 1.2 Volt to a single higher level, like 1.45 Volt.
They would have saved on components to do the switching between 2D and 3D.
Nobody does anything without a reason.
The fact that "Most people with the problems never overvolted their cards and were at 1.2V all the time" is no prove against my assumption that a lower voltage extends life.
So to disagree you have to come with something more substantial.

[Orion24]

If a lower voltage does not extend life, why has EVGA not simply increased the voltage from 1.2 Volt to a single higher level, like 1.45 Volt.
They would have saved on components to do the switching between 2D and 3D.
Nobody does anything without a reason.
The fact that "Most people with the problems never overvolted their cards and were at 1.2V all the time" is no prove against my assumption that a lower voltage extends life.
So to disagree you have to come with something more substantial.Yup, my mistake here. I thought you were refering to it as the reason why 7900 cards have problems (probably because I was reading another thread that was about it, at the same time)

[Demo]

so the bios version mod only works if you have the new eVGA PCB rev right ? the ones that have that swtiching resistors as shown on the pics? or can we install them our selves

[t024484]

so the bios version mod only works if you have the new eVGA PCB rev right ? the ones that have that swtiching resistors as shown on the pics? or can we install them our selves
I do not understand what you mean with "bios version mod".
This harware mod works with all the 7900GT boards that have not installed this extra hardware.
What do you mean with switching resistors?

[Demo]

What i ment is, this volt modding via bios only works if you add those missing components on your card and allow voltage swtiching ?

[t024484]

What i ment is, this volt modding via bios only works if you add those missing components on your card and allow voltage swtiching ?
Yes that is true. You have to add three components, and you need to install the right BIOS.

[aussie-revhead]

Hi guys , I have a 512 Calibre with a maze4 acetal fitted and I want to volt mod it , can I use the volt mods in this thread or should I use another type of volt mod ? How do I mod the bios for vid1 and 2 ? What bios can I use for my card ? Can I dip switch those bridges to allow the mod to be turned off ? This would not be needed if the vid1/2 mod works , but would be nice if it doesnt .

Any help would be great .

:rolleyes:

[aussie-revhead]

I have made the same voltage switching option to a standard 7900GT. This modification can be applied to any standard 7900GT board. You will need a BIOS that switches from VID 0 in 2D to VID 1 when in 3D mode. You can check if your BIOS does this, with the monitor function of Riva Tuner going from 2D to 3D.
You could use the EVGA 7900GT-SS BIOS for this purpose, but you can just as well change your own BIOS with Nibitor, using the advanced voltage editor.
You will also need some soldering skills.

The components that I used, are 2 dual schottky diodes, type BAT54C, and 1 N type Mosfet BSS670S2L, that's all. I bought them from Farnell.com.
Any dual schottky diode with common cathode will do , and any low power N channel Mosfet with less then 10 Ohm channel resistance when switched on is O.K.
The board in the unmodified state looks like:



And after Modification:



Red gives you +0.05 Volt
Yellow gives +0.1 Volt
Purple gives +0.2 Volt

So with the standard 5Kohm resistor giving you 1.2 Volt in 2D, you can now switch to anything between 1.2 and 1.55 Volt in 3D.

What is missing from this post ? You mention hardware parts and dont show where they go . I want to mod my 7900GT Calibre 512 but want to make sure I dont stuff it up . Any help would be great .

:D

[t024484]

What is missing from this post ? You mention hardware parts and dont show where they go . I want to mod my 7900GT Calibre 512 but want to make sure I dont stuff it up . Any help would be great .

:D
The pictures are erased by xtreme. but they are republished in posting #24.
I do not know what a calibre 512 looks like, so it will be impossible for me to give you any help without a picture.

[aussie-revhead]

The area in question in post #24 looks the same as my Calibre . I saw those pics but where are the dip switches and mosfet involved ?

:rolleyes:

http://imagestore.ugbox.net/thumb/DSCF0363_a18ad65f0be51ac4349cab0.jpg (http://imagestore.ugbox.net/aview/DSCF0363_a18ad65f0be51ac4349cab0)
Click to view full-sized image! (http://imagestore.ugbox.net/aview/DSCF0363_a18ad65f0be51ac4349cab0)
Hosted by UGBox Image Store (http://imagestore.ugbox.net)

[p0tter]

Nice, good info

[t024484]

The area in question in post #24 looks the same as my Calibre . I saw those pics but where are the dip switches and mosfet involved ?

What dip switches are you referring to ?
I soldered two dual schottky diodes and one mosfet on the board, You can see where when comparing the two pictures.

[aussie-revhead]

OK I see now , pardon my noobness , this looks out of the reach of a noob like me , and Im not sure where I would get components like these here anyway .

Can I use the other volt mod shown elsewhere for 7900GT ? Can you also point me to a vmem mod ? Do you believe that vmem mod is going to kill my card , as I read elsewhere ?

:rolleyes:

[t024484]

OK I see now , pardon my noobness , this looks out of the reach of a noob like me , and Im not sure where I would get components like these here anyway .

Can I use the other volt mod shown elsewhere for 7900GT ? Can you also point me to a vmem mod ? Do you believe that vmem mod is going to kill my card , as I read elsewhere ?

:rolleyes:
Use the latest most simple variant of the voltmod, and forget about Vmem modding.

[aussie-revhead]

With so many pages on this subject , could you please point me to the lastest most simple version of the volt mod? Will gpu volt mod also increase my mem clocks? I currently get 600/800 in standard form with ATItool . What is safe max vgpu for water cooled vid card? I got just under 10000 in 3D05 with a 146 , so my E6400 will help that .

I will try 1.55v mod for sure but considering 1.7 ( except for the soldering )

;)

[t024484]

With so many pages on this subject , could you please point me to the lastest most simple version of the volt mod? Will gpu volt mod also increase my mem clocks? I currently get 600/800 in standard form with ATItool . What is safe max vgpu for water cooled vid card? I got just under 10000 in 3D05 with a 146 , so my E6400 will help that .

I will try 1.55v mod for sure but considering 1.7 ( except for the soldering )

;)
Look in this thread http://www.xtremesystems.org/forums/showthread.php?t=94177. First print the pictures in posting 640 page26, and then read posting 2 Page1, posting 500 page20 and posting 543 page 22.

[aussie-revhead]

Thanks for that , here is a pic of a modded card that looks very well done , but what do they all do ?

http://www.ocforums.com/showthread.php?t=454737

Or what about this one ? This looks much easier than yours , but 1.55 max :

http://forum.overclockers.com.au/showpost.php?p=5714153&postcount=58

And these pics look informative :

http://sg.vr-zone.com/?i=3330&s=2

:rolleyes:

[t024484]

Thanks for that , here is a pic of a modded card that looks very well done , but what do they all do ?

http://www.ocforums.com/showthread.php?t=454737

Or what about this one ? This looks much easier than yours , but 1.55 max :

http://forum.overclockers.com.au/showpost.php?p=5714153&postcount=58

And these pics look informative :

http://sg.vr-zone.com/?i=3330&s=2

:rolleyes:
Read better. No one has found an easier way to voltmod than I did.
In the picture shown it is the lower of the three mods. No connection to ground is needed. If you want to go beyond 1.55Volt ( why should you ?) you also have to replace a resistor changing the base from 1.2 to 1.5Volt.

[aussie-revhead]

The mod on ocau forum looks easier than yours , when I find the source pic I will post it .

:rolleyes:

Here , in post 133 :

http://www.ocforums.com/showthread.php?t=454737&page=5

:D

[aussie-revhead]

Is there a bios for my 512 Calibre to allow use of this switching mod ?

Can you tell me what vid cards have this hardware already on them ? You mentin EVGA 7900GT SS , are there any others ? I was told elsewhere that all late 7900GT and 7600GT have dual voltages , is this correct ?

:D

[t024484]

The mod on ocau forum looks easier than yours , when I find the source pic I will post it .

:rolleyes:

Here , in post 133 :

http://www.ocforums.com/showthread.php?t=454737&page=5

:D
If it looks easier to you , it is because you haven't read well. Sorry, no offend, but it is a fact.
You keep asking questions, which is completely O.K., but you do not take the time to really understand things. Make one step at the time and not twenty.
The only 7900 boards that I know of that are switching their GPU voltage are the 7900GTX and a few EVGA 7900GT boards.
To answer your Bios question, look into your Bios with Nibitor, and see if this option is available, then check with Rivatuner if the VID is really switching.
But again, why do you want to know this if you are not going to solder those extra components, and why do you want to go beyond 1.55 Volt.
Take my advice, start with a GPU voltmod to 1.5 Volt. This is just connecting two sets of two points together. Forget the Vmem mod, and see to what frequency your board is working troublefree.
Eventually after having done that, you could increase the conversion frequency by pencil modding and thats it. Go no further if you are not a skilled soldering guy.

[aussie-revhead]

I am sorry if I ask too many questions , I can not afford to blow up my vid card but I love overclockign and benchmarking , so I am ambitious . :D

I will first do 1.5 mod then see where we go from there . If switching is available I may look at soldering the extra components .

My pc isnt running yet so I cant look at bios yet , but I will .

Thank you for your help .

:rolleyes:

[Demo]

@aussie-revhead

t024484's mod is quite simple also but it does have a draw back of having to remember which trace to remove if you want to step down a few volts, as for that volt mod you posted it has an advantage of using masking tapes to act as a "bridge" so you can toggle the mod on and off.. altho that mod is a bit hard for first timers who use conductive ink ( not pen )

Click (http://xs206.xs.to/xs206/06376/maskingmode.jpg) for image ( 1600x1200 )

[aussie-revhead]

You laid the tape down before you drew the conductive lines so you can peel the tape off and break the lines ? Not bad , but is there a way to attach a small switch to the pcb without soldering ? I wouldnt mind attaching a switch to disable the 1.55 mod when its not needed , to extend vid card life . I thought all those soldering pics looked Ok until I looked at the card and saw how small all those bits are .

Its a crap drawing , but this is what I mean :

51402

Why does this file get bigger when I shrink it ?

:rolleyes:

[t024484]

You laid the tape down before you drew the conductive lines so you can peel the tape off and break the lines ? Not bad , but is there a way to attach a small switch to the pcb without soldering ? I wouldnt mind attaching a switch to disable the 1.55 mod when its not needed , to extend vid card life . I thought all those soldering pics looked Ok until I looked at the card and saw how small all those bits are .

You are in the wrong thread, go to the sticky.

[aussie-revhead]

That was in reply to Demos post , but thanks .

;)

[Demo]

That switching method can also work, and yes i placed the masking tape b4 i draw the connection.

[wildcard]

Silly question, what are you supposed to do at those colored locations? Connect them together (the two points within the color code)? attach a 50k resistor? Something else?

This wasn't immediately clear to me.

Thanks!



Red gives you +0.05 Volt
Yellow gives +0.1 Volt
Purple gives +0.2 Volt

[t024484]

Silly question, what are you supposed to do at those colored locations? Connect them together (the two points within the color code)? attach a 50k resistor? Something else?

This wasn't immediately clear to me.

Thanks!
connect them

[Orion24]

All right, I went to the local supplier with the ordering page of Farnell.com and said he could place the order for these items. I ordered them in quantities of 10 and 5, so I have some spears; but it was only until I heard the price I had to pay: 81 Euros! Oh man! :eek: You should have seen my face when I heard it. These cost 1-2 Euros in Farnell.com. I decreased the order to 5 & 5 quantities (minimum I could order)

[Orion24]

OK done it for my first 7900GT and works. Nice guide here. :clap:

Only note is that modding my existing XFX BIOS with the advanced voltage editor of NBITOR didn't do anything. VID 0 and VID 1 both game me 1.2V, or there has been no voltage switching. Maybe the correct VID for here was 2,3 or 4, or maybe the BIOS editor did not properly work. Eitherway I had to use the EVGA BIOS.

Now, time to mod the second 7900GT

[Roger_D25]

Unfortunetly not all cards/BIOS can be modified for separate 2d/3d voltages. If I'm not mistaken I believe that the card in question needs to have certain components installed for this to be possible?

[t024484]

Unfortunetly not all cards/BIOS can be modified for separate 2d/3d voltages. If I'm not mistaken I believe that the card in question needs to have certain components installed for this to be possible?
You are probably wrong. All 7900Gt boards can be modified, of course with the exception of those boards that have already been modified by the supplier
like the EVGA SS.
And if your BIOS does not switch the VID correctly. simply use the EVGA BIOS.

[Roger_D25]

Thanks for the correction t024484, I have assumed for sometime now that you had to modify both the card and BIOS to get the 2d/3d voltage change to occur on cards that didn't come that way? For example with my 2nd RMA'ed 7900GT (7900GT CO) I actually tried flashing the BIOS with the eVGA 7900GT SS version hoping to get the separate 2d/3d voltage changes. Unfortunetly nothing happened (had 1.2v on both 2d/3d), from what I understand it would have been possible but only by modifying the card with some additional components, and then modifying the BIOS.

I could have misunderstood Orian24 but I thought he was asking if it was possible by only modifying BIOS? In fact you are one of the few people who have come up with a step-by-step method for adding the correct hardware so that their non-switching cards can switch voltages in 2d/3d modes?

On a different note, it is possible to modify my 7900GT SS card's 3d voltage, (which already has the added components for separate 2d/3d voltage switching) so that it goes from the stock level of 1.45v to say 1.5v or 1.55v corerct? I have a feeling you have explained this many times but I have been unable to piece the info together enough to make it happen.

Do you remember if you have already posted this info t024484 in this thread or on extremesystems somewhere? You certainly don't have to explain it once again but if you could point me in the right direction that would be great!

[t024484]

Thanks for the correction t024484, I have assumed for sometime now that you had to modify both the card and BIOS to get the 2d/3d voltage change to occur on cards that didn't come that way? For example with my 2nd RMA'ed 7900GT (7900GT CO) I actually tried flashing the BIOS with the eVGA 7900GT SS version hoping to get the separate 2d/3d voltage changes. Unfortunetly nothing happened (had 1.2v on both 2d/3d), from what I understand it would have been possible but only by modifying the card with some additional components, and then modifying the BIOS.

I could have misunderstood Orian24 but I thought he was asking if it was possible by only modifying BIOS? In fact you are one of the few people who have come up with a step-by-step method for adding the correct hardware so that their non-switching cards can switch voltages in 2d/3d modes?

On a different note, it is possible to modify my 7900GT SS card's 3d voltage, (which already has the added components for separate 2d/3d voltage switching) so that it goes from the stock level of 1.45v to say 1.5v or 1.55v corerct? I have a feeling you have explained this many times but I have been unable to piece the info together enough to make it happen.

Do you remember if you have already posted this info t024484 in this thread or on extremesystems somewhere? You certainly don't have to explain it once again but if you could point me in the right direction that would be great!
You are right, you have to modify the board, and you need the right Bios to make use of the added hardware. Only modding the hardware brings nothing, and installing the right Bios on an unmodded card does also nothing.
The extra hardware are switches, and those switches have to be switched by the right Bios.

It is very well possible to make an SS board switch to a higher voltage than the factory installed 1.45Volt. Look at the second picture in posting #1 of this thread. EVGA has already made the purple and the the red connection, giving you 0.2 + 0.05 volt extra over the 1.2 Volt, totalling to 1.45 Volt.
If you additionally make the yellow connection, you will add another 0.1 Volt giving you 1.55 Volt.

[Roger_D25]

After comparing my card to those pictures earlier today (and before I read your recent post) I came to the same conclusion but thought there was no way it was that easy, lol! I'm going to give it a try tonight, thanks again for taking the time to re-explain that for the thousandth time, lol! I should have pulled my card first to compare it before posting that question as I probably could have done it on my own.

[Demo]

I've been running my Inno3D 7900GT at 1.55v with VF900Cu-Led a few days after i got it since July 04,2006 would it be safe to assume that my card is in good working order ? been running at 650/800.

[Roger_D25]

Demo,
Did your Inno3D card come with a stock voltage of 1.2v in both 2d/3d modes? Also do you remember what clockspeed your core was able to run at while still being stable before the voltage mod? Last but not least is 650Mhz the highest your card runs while still being stable @ the current voltage of 1.55v?

My card's GPU is still running at stock voltage (1.45v) but I have slightly modified the memory voltage which allows me to run at 860-870Mhz while still being stable. That is a good 80-100Mhz higher than it would run at stock voltages. I'm about to mod the GPU to run at 1.55v, I'm curious as to what I'll be able to run the core at after that mod while still being stable. Although I can currenlty run my core at 670Mhz it's more stable at 650Mhz and that is where I leave it for gaming and everyday use. I'll post back later today after the mod and let you guys know if it allowed my core any additional headroom.

[Roger_D25]

t024484,
Well I just finished connecting the "Yellow" pads together for an extra 0.1v and it seems to have worked fine. The only thing is that my card is now always running at 1.55v in both 2d and 3d, was this to be expected? To be accurate I should say that my card runs at 1.548v from bootup until I start a 3d application, once the application starts the voltage jumps to 1.551v, then it again lowers to 1.548v once I close the application? Do you have any thoughts on this (I'm a bit worrried because I have a feeling this isn't supposed to happen.

One last thing, since my card is a Signiture Series the "Red" and "Purple" connections are already connected because my stock 3d voltage is 1.45v, well those connections are not simply connected with a bit of solder but they are actually connected with what looks like resistors or small capacitors (not knowledgeable enough to know which it is, or if it is either of those two things). Either way it is not just a simple connection. Do you happen to know anything about that or is it normal? As always thanks for your help and time!

[t024484]

t024484,
Well I just finished connecting the "Yellow" pads together for an extra 0.1v and it seems to have worked fine. The only thing is that my card is now always running at 1.55v in both 2d and 3d, was this to be expected? To be accurate I should say that my card runs at 1.548v from bootup until I start a 3d application, once the application starts the voltage jumps to 1.551v, then it again lowers to 1.548v once I close the application? Do you have any thoughts on this (I'm a bit worrried because I have a feeling this isn't supposed to happen.

One last thing, since my card is a Signiture Series the "Red" and "Purple" connections are already connected because my stock 3d voltage is 1.45v, well those connections are not simply connected with a bit of solder but they are actually connected with what looks like resistors or small capacitors (not knowledgeable enough to know which it is, or if it is either of those two things). Either way it is not just a simple connection. Do you happen to know anything about that or is it normal? As always thanks for your help and time!
The components used for RED and Purple are zero ohm resistors, also the same as a dot of solder. That yellow is giving you 1.55Volt all the time, can only mean that either you have damaged something, or you have made more connections than just the two points in yellow.

The black component with three pins below the red and yellow connection with the text Q517 next to it, should show on the side with only one pin, 3.3 Volt in 2d and 0 Volt in 3D.
But before you try measuring this, it may be better to remove your yellow connection, and see if everything is again like it was before.

[Roger_D25]

Interesting t024484, I didn't think that was how it was supposed to be. I've been running it this way since yesterday afternoon with no problems so far (I only ran it this long because I had no idea if this was suppose to happen or not, otherwise I would have pulled it out). Also when I connected the two points I used conductive ink like many do. Because I've learned from my mistakes though I didn't use the pen for the connection, I put a tiny dab on the end of toothpic and with the aid of a magnifying glass and additional light I very carefully dapped between the two points. What I'm getting at here is there is no way I connected anything except those two points. Also I used my meters continuity tester to make sure that was the case (although I don't know how effective that was since many of those points have some sort of continuity between them)? Finally I used some isopropyl alcohol afterwards to completly clean that area of the card (fingerprints etc..).

I should add one more thing, I set my meter up so that it was measureing the GPU voltage without having to hold the probes myself (I just put the meter by my keyboard while measureing so I could actively monitor voltage). Anyway I measured from before hitting the power button until WinXP booted. Well from initiallly hitting the power button until right before WinXP fully loaded the voltage was only 1.2v on the money. Then right when WinXP fully loaded it jumped to 1.55v? I'll wait to hear back before I do anything but I assume the best thing to do is remove the connection and make sure things go back to normal first and then take it from there. Thank you very much t024484 for your help and time with this, it is very much apprecaited!

[t024484]

Interesting t024484, I didn't think that was how it was supposed to be. I've been running it this way since yesterday afternoon with no problems so far (I only ran it this long because I had no idea if this was suppose to happen or not, otherwise I would have pulled it out). Also when I connected the two points I used conductive ink like many do. Because I've learned from my mistakes though I didn't use the pen for the connection, I put a tiny dab on the end of toothpic and with the aid of a magnifying glass and additional light I very carefully dapped between the two points. What I'm getting at here is there is no way I connected anything except those two points. Also I used my meters continuity tester to make sure that was the case (although I don't know how effective that was since many of those points have some sort of continuity between them)? Finally I used some isopropyl alcohol afterwards to completly clean that area of the card (fingerprints etc..).

I should add one more thing, I set my meter up so that it was measureing the GPU voltage without having to hold the probes myself (I just put the meter by my keyboard while measureing so I could actively monitor voltage). Anyway I measured from before hitting the power button until WinXP booted. Well from initiallly hitting the power button until right before WinXP fully loaded the voltage was only 1.2v on the money. Then right when WinXP fully loaded it jumped to 1.55v? I'll wait to hear back before I do anything but I assume the best thing to do is remove the connection and make sure things go back to normal first and then take it from there. Thank you very much t024484 for your help and time with this, it is very much apprecaited!
If the switch to 1.55Volt already happens when Windows is loading, it almost sounds as if your EVGA Bios is doing something wrong.
You can check with RivaTuner if VID 1 is active in 2D and if it stays active in 3D. If this is the case, your Bios should be modified.
What should happen is that Rivatuner shows VID 0 in 2D and VID 1 in 3d.
This VID signal is responsible for switching between 1.2Volt in 2D to 1.45 Volt in 3D(or to 1.55 Volt with the yellow connection) .

[Roger_D25]

I can't believe I forgot about this t024484 but about a week after I got the card I flashed the BIOS because eVGA sent it out to me with the 7900GT CO BIOS installed because that is the card I RMAed (clockspeeds 500/1500). I flashed it with the SS BIOS but I also changed a few things with NiBiTor before the flash. Besides clockspeeds I also changed the 2D voltage to be the same as 3D voltage. At the time I did it to test whether or not it would allow better clockspeeds with the intention of flashing it back to separate 2D/3D voltages but never did it! Hence why even after doing the 1.55v GPU mod it ran at 1.55v in both 2D and 3D! The only reason I realized this was because I threw the meter on it during system bootup (since it ran at 1.2v throughout bootup and only changed to 1.55v once WinXP loaded I knew it might be a BIOS issue and not hardware related, just as you suggested above). So sorry to have asked so many questions without fully testing everything first (BIOS and voltages), if I did I probably wouldn't have bothered anyone here!

[Demo]

Demo,
Did your Inno3D card come with a stock voltage of 1.2v in both 2d/3d modes? Also do you remember what clockspeed your core was able to run at while still being stable before the voltage mod? Last but not least is 650Mhz the highest your card runs while still being stable @ the current voltage of 1.55v?

My card's GPU is still running at stock voltage (1.45v) but I have slightly modified the memory voltage which allows me to run at 860-870Mhz while still being stable. That is a good 80-100Mhz higher than it would run at stock voltages. I'm about to mod the GPU to run at 1.55v, I'm curious as to what I'll be able to run the core at after that mod while still being stable. Although I can currenlty run my core at 670Mhz it's more stable at 650Mhz and that is where I leave it for gaming and everyday use. I'll post back later today after the mod and let you guys know if it allowed my core any additional headroom.

It came with a 1.2v in both 2d/3d modes. i only had a max of 520Mhz core OC with the stock volts, raised it to 1.50 and i was stuck at 640 ( LOL ) so i decided to raise it at 1.55 which gave me a max of 670 also but i run it at 650 24/7. i didnt bother to mod the memory yet as im not confident enough with the pencil mod,

[Shpoon]

Does anyone know where I can get the most recent driver for the card? (If I do this mod), and do I install the drivers first, then do hte voltmod, or other way around?

[Roger_D25]

Shpoon,
If your just talking about the regular Nvidia graphics card driver than it doesn't matter. Voltmodding the card doesn't affect the driver and vise-versa. That is to say that you can just uninstall the card, do your mods, and then reinstall the card with no problems at all. The only thing I would reccomend is to set the clock speeds to default speeds before you do the mod but I really don't think it matters.

PS, Somebody please correct me if I'm wrong!

[Shpoon]

Hmm, I thought it would need a special driver to run at independant 2d/3d voltages?

[Roger_D25]

Oh, you may have confused a special driver with the cards BIOS version. You would need to use a different BIOS version to take advantage of separte 2d/3d voltages on a card that didn't come that way stock. In fact Shpoon that is exaclty what this whole thread is about. t024484 explains what would have to be done to take a stock card which runs at only 1.2v and modify it to run at separate 2d/3d voltages!

[Shpoon]

Ya, I got that part, currently I'm using the old "1.45V always) mod. I was wondering if anyone had a link to the newest card bios (I said drivers).

[t024484]

Ya, I got that part, currently I'm using the old "1.45V always) mod. I was wondering if anyone had a link to the newest card bios (I said drivers).
http://www.mvktech.net/

[Shpoon]

Thanks very much :)

[aussie-revhead]

Hi guys , I did pass the explanation here for the frequency mod but cant find it now , could you please link me to the mem frequency mod for 7900GT ?

My Calibre has been running up to 750/840 with 1.55vmod and water cooling , will the frequency mod help me get more out of this card ? I get a random flicker of colour during post when the screen is blank , no problems during any other situation , I was told the freq mod will fix this , is this correct ?

Any help would be great .

BTW My best score so far in 3D06 is 7150 :D

[Edit] I found it in the first post of the sticky , is this still current ? My questions still stand .

:-P

[t024484]

Hi guys , I did pass the explanation here for the frequency mod but cant find it now , could you please link me to the mem frequency mod for 7900GT ?

My Calibre has been running up to 750/840 with 1.55vmod and water cooling , will the frequency mod help me get more out of this card ? I get a random flicker of colour during post when the screen is blank , no problems during any other situation , I was told the freq mod will fix this , is this correct ?

Any help would be great .

BTW My best score so far in 3D06 is 7150 :D

[Edit] I found it in the first post of the sticky , is this still current ? My questions still stand .

:-P
Yes it is still valid.

[aussie-revhead]

Thanks , in what ways will the freq mod help me ?

:rolleyes:

[ziddey]

where's a good place to order from in america? that place linked has a crazy minimum order price

[errol8000]

The components that I used, are 2 dual schottky diodes, type BAT54C, and 1 N type Mosfet BSS670S2L, that's all. I bought them from Farnell.com.
Any dual schottky diode with common cathode will do , and any low power N channel Mosfet with less then 10 Ohm channel resistance when switched on is O.K.

Thanks t024484 for your cool volt switching guide can you please tell me if
this mosfet is fine.. Thank you.

BSS123

MOSFET, N SOT-23 Transistor type:MOSFET Transistor polarity:N Voltage, Vds max:100V Case style:SOT-23 Current, Id cont:0.17A Current, Idm pulse:0.68A Power, Pd:0.36W Resistance, Rds on:6R SMD:1 Depth, external:2.5mm Length / Height, external:1.12mm Marking, SMD:SA Pins, No. of:3 Power dissipation:0.36W Temperature, current:25°C Temperature, full power rating:25°C Transistors, No. of:1 Voltage, Vgs th max:2V Width, external:3.05mm Width, tape:8mm